Publications of NIPGR Scientists
Permanent URI for this communityhttps://ndkr-library.nipgr.ac.in/handle/123456789/1
Browse
12 results
Search Results
Item Wheat TaNACα18 functions as a positive regulator of high-temperature adaptive responses and improves cell defense machinery(John Wiley & Sons, 2024) Mishra, Divya; Shekhar, Shubhendu; Subba, Pratigya; Prasad, T S Keshava; Chakraborty, Subhra; Chakraborty, NiranjanGlobal wheat production amounted to >780 MMT during 2022-2023 whose market size are valued at >$128 billion. Wheat is highly susceptible to high-temperature stress (HTS) throughout the life cycle and its yield declines 5-7% with the rise in each degree of temperature. Previously, we reported an array of HTS-response markers from a resilient wheat cv. Unnat Halna and described their putative role in heat acclimation. To complement our previous results and identify the key determinants of thermotolerance, here we examined the cytoplasmic proteome of a sensitive cv. PBW343. The HTS-triggered metabolite reprograming highlighted how proteostasis defects influence the formation of an integrated stress-adaptive response. The proteomic analysis identified several promising HTS-responsive proteins, including a NACα18 protein, designated TaNACα18, whose role in thermotolerance remains unknown. Dual localization of TaNACα18 suggests its crucial functions in the cytoplasm and nucleus. The homodimerization of TaNACα18 anticipated its function as a transcriptional coactivator. The complementation of TaNACα18 in yeast and overexpression in wheat demonstrated its role in thermotolerance across the kingdom. Altogether, our results suggest that TaNACα18 imparts tolerance through tight regulation of gene expression, cell wall remodeling and activation of cell defense responses.Item High temperature stress responses and wheat: Impacts and alleviation strategies(Elsevier B.V., 2021) Mishra, Divya; Shekhar, Shubhendu; Chakraborty, Subhra; Chakraborty, NiranjanOver the past century, the average surface temperature and recurrent heatwaves have been steadily rising, affecting the yield potential of most food crops including bread wheat, the second most important caloric source, but is particularly vulnerable to the impacts of elevated temperatures. Significantly, the past decade has witnessed tremendous advancements in multiomics approaches to extract the key regulators that influence the adaptive responses to high temperature stress (HTS). With the help of genetic engineering technologies, transgenic wheat plants have been developed showing resistance to HTS without hampering productivity. In this review, we described the effect of rising temperature at a global scale and the drastic impacts on crops, particularly on wheat production. Also, this review is focused on accomplishing a deeper understanding of the genetic and molecular basis of HTS responses of crop plants, wheat in particular along with current strategies and technologies to generate thermotolerant varieties. Collective strategy and identified thresholds of HTS tolerance and susceptibility will contribute to the value-added modelling of wheat growth and yield under predictable future climate conditions.Item Wheat 2-Cys peroxiredoxin plays a dual role in chlorophyll biosynthesis and adaptation to high temperature(John Wiley & Sons, 2021) Mishra, Divya; Shekhar, Shubhendu; Chakraborty, Subhra; Chakraborty, NiranjanThe molecular mechanism of high temperature stress (HTS) response, in plants, has so far been investigated using transcriptomics, while the dynamics of HTS‐responsive proteome remain unexplored. We examined the adaptive responses of the resilient wheat cultivar ‘Unnat Halna’ and dissected the HTS‐responsive proteome landscape. This led to the identification of 55 HTS‐responsive proteins (HRPs), which are predominantly involved in metabolism and defense pathways. Interestingly, HRPs included a 2‐cysteine peroxiredoxin (2CP), designated Ta2CP, presumably involved in stress perception and adaptation. Complementation of Ta2CP in yeast and heterologous expression in Arabidopsis demonstrated its role in thermotolerance. Both Ta2CP silencing and overexpression inferred the involvement of Ta2CP in plant growth and chlorophyll biosynthesis. We demonstrated that Ta2CP interacts with protochlorophyllide reductase b, TaPORB. Reduced TaPORB expression was found in Ta2cp‐silenced plants, while upregulation was observed in Ta2CP‐overexpressed plants. Furthermore, the downregulation of Ta2CP in Taporb‐silenced plants and reduction of protochlorophyllide in Ta2cp‐silenced plants suggested the key role of Ta2CP in chlorophyll metabolism. Additionally, the transcript levels of AGPase1 and starch were increased in Ta2cp‐silenced plants. More significantly, HTS‐treated Ta2cp‐silenced plants showed adaptive responses despite increased reactive oxygen species and peroxide concentrations, which might help in rapid induction of high‐temperature acclimation.Item Carboxylate clamp tetratricopeptide repeat (TPR) domain containing Hsp90 cochaperones in Triticeace: an insight into structural and functional diversification(Elsevier B.V., 2018) Mishra, Divya; Shekhar, Shubhendu; Chakraborty, Subhra; Chakraborty, NiranjanThe molecular chaperones serve as surveillance molecules that mediates regulatory crosstalk between protein folding and degradation pathways under natural and stress conditions. In present study, we focused on the diversification and role of tetratricopeptide repeat (TPR) domain containing Hsp90 cochaperones. These cochaperone were recognized by the presence of three motifs of TPR with the basic conserved residues often referred to as carboxylate clamp (CC). A total of 213 putative CC-TPRs were found in Triticeace, clustered into 16 groups, amongst which few CC-TPR families such as TPR-RPAP3 and TPR-SMYD were documented. Domain architecture and genomic organization revealed that CC-TPRs are very diverse in nature. Evolutionary analyses showed that CC-TPRs are conserved, stable and ubiquitous in nature. Analysis of available RNA-seq data revealed a high degree of tissue-specific expression of 1-TPR and TaTPR-FKBP family members at various developmental stages. The transcripts of TaCC-TPRs displayed differential expression in two contrasting wheat cultivars under abiotic stress conditions. Complementation and heterologous expression of TaTPR-FKBP5 in yeast conferred abiotic stress tolerance. Together, these results provide a glimpse into the genetic diversity and evolution of CC-TPRs in Triticeace, which would help to better understand of how TPR-domain cochaperones function in plants.Item Cultivar-specific high temperature stress responses in bread wheat (Triticum aestivum L.) associated with physicochemical traits and defense pathways(Elsevier B.V., 2017) Mishra, Divya; Shekhar, Shubhendu; Agrawal, Lalit; Chakraborty, Subhra; Chakraborty, NiranjanThe increasing global temperature by 1°C is estimated to reduce the harvest index in a crop by 6%, and this would certainly have negative impact on overall plant metabolism. Wheat is one of the most important crops with global annual production of over 600million tonnes. We investigated an array of physicochemical and molecular indexes to unravel differential response of nine commercial wheat cultivars to high temperature stress (HTS). The reduced rate in relative water content, higher membrane stability, slow chlorophyll degradation and increased accumulation of proline and secondary metabolites ingrained higher thermotolerance in cv. Unnat Halna, among others. The altered expression of several stress-responsive genes, particularly the genes associated with photosynthesis, heat shock proteins and antioxidants impinge on the complexity of HTS-induced responses over different genetic backgrounds and connectivity of adaptive mechanisms. This may facilitate the targeted manipulation of metabolic routes in crops for agricultural and industrial exploitation.Item Ectopic expression of amaranth seed storage albumin modulates photoassimilate transport and nutrient acquisition in sweetpotato(Nature Publishing Group, 2016) Shekhar, Shubhendu; Agrawal, Lalit; Mishra, Divya; Buragohain, Alak Kumar; Unnikrishnan, Mullath; Mohan, Chokkappan; Chakraborty, Subhra; Chakraborty, NiranjanStorage proteins in plants, because of high nutrient value, have been a subject of intensive investigation. These proteins are synthesized de novo in the cytoplasm and transported to the storage organelles where they serve as reservoir of energy and supplement of nitrogen during rapid growth and development. Sweetpotato is the seventh most important food crop worldwide, and has a significant contribution to the source of nutrition, albeit with low protein content. To determine the behaviour of seed storage proteins in non-native system, a seed albumin, AmA1, was overexpressed in sweetpotato with an additional aim of improving nutritional quality of tuber proteins. Introduction of AmA1 imparted an increase in protein and amino acid contents as well as the phytophenols. The proteometabolomics analysis revealed a rebalancing of the proteome, with no significant effects on the global metabolome profile of the transgenic tubers. Additionally, the slower degradation of starch and cellulose in transgenic tubers, led to increased post-harvest durability. Present study provides a new insight into the role of a seed storage protein in the modulation of photoassimilate movement and nutrient acquisition.Item Comparison of proteomic and metabolomic profiles of two contrasting ecotypes of sweetpotato (Ipomoea batata L)(Elsevier B.V., 2016) Shekhar, Shubhendu; Mishra, Divya; Gayali, Saurabh; Buragohain, Alak Kumar; Chakraborty, Subhra; Chakraborty, NiranjanSweetpotato has long been acknowledged as a significant contributor of global caloric needs, which continues to be of remarkable economic value. It is an important staple and emergency food in many countries and its annual world production hovers to about 130 million tons. The tubers act as sink and compete for the available photoassimilates eventually leading to the acquisition of nutrients and phytochemicals. Differential display of genes or gene-products, and metabolites causes differences in nutritive value of closely related ecotypes. To better understand the molecular basis for differential nutrient availability and phytochemicals, and exploit the natural genetic variation(s), we aimed at developing proteometabolic profiles of two contrasting ecotypes of sweetpotato. Proteomic analyses led to the identification of 1541 and 1201 proteins in orange fleshed and white fleshed sweetpotato ecotypes, respectively, presumably associated with binding, followed by catalytic, transferase, hydrolase, kinase and transporter activities. Furthermore, metabolome profiling revealed 148 and 126 metabolites in cv. OFSP and WFSP, respectively. This study would provide a basis for future comparative proteometabolomic efforts for sweetpotato, in particular and tuber crops in general. The results would expand our understanding of the proteome as well as metabolome and give new insights into how ecotype-specific traits are developed.Item Comparative analysis of phytochemicals and nutrient availability in two contrasting cultivars of sweet potato (Ipomoea batatas L.)(Elsevier B.V., 2014) Shekhar, Shubhendu; Mishra, Divya; Buragohain, Alak Kumar; Chakraborty, Subhra; Chakraborty, NiranjanSweet potato ranks as the world's seventh most important food crop, and has major contribution to energy and phytochemical source of nutrition. To unravel the molecular basis for differential nutrient availability, and to exploit the natural genetic variation(s) of sweet potato, a series of physiochemical and proteomics experiment was conducted using two contrasting cultivars, an orange-fleshed sweet potato (OFSP) and a white-fleshed sweet potato (WFSP). Phytochemical screening revealed high percentage of carbohydrate, reducing sugar and phenolics in WFSP, whereas OFSP showed increased levels of total protein, flavonoids, anthocyanins, and carotenoids. The rate of starch and cellulose degradation was found to be less in OFSP during storage, indicating tight regulation of gene(s) responsible for starch-degradation. Comparative proteomics displayed a cultivar-dependent expression of proteins along with evolutionarily conserved proteins. These results suggest that cultivar-specific expression of proteins and/or their interacting partners might play a crucial role for nutrient acquisition in sweet potato.Item Characterization of the nuclear proteome of a dehydration-sensitive cultivar of chickpea and comparative proteomic analysis with a tolerant cultivar(John Wiley & Sons Ltd, 2013) Subba, Pratigya; Kumar, Rajiv; Gayali, Saurabh; Shekhar, Shubhendu; Parveen, Shaista; Pandey, Aarti; Datta, Asis; Chakraborty, Subhra; Chakraborty, NiranjanWater deficit or dehydration hampers plant growth and development, and shrinks harvest size of major crop species worldwide. Therefore, a better understanding of dehydration response is the key to decipher the regulatory mechanism of better adaptation. In recent years, nuclear proteomics has become an attractive area of research, particularly to study the role of nucleus in stress response. In this study, a proteome of dehydration-sensitive chickpea cultivar (ICCV-2) was generated from nuclei-enriched fractions. The LC-MS/MS analysis led to the identification of 75 differentially expressed proteins presumably associated with different metabolic and regulatory pathways. Nuclear localisation of three candidate proteins was validated by transient expression assay. The ICCV-2 proteome was then compared with that of JG-62, a tolerant cultivar. The differential proteomics and in silico analysis revealed cultivar-specific differential expression of many proteins involved in various cellular functions. The differential tolerance could be attributed to altered expression of many structural proteins and the proteins involved in stress adaptation, notably the ROS catabolising enzymes. Further, a comprehensive comparison on the abiotic stress-responsive nuclear proteome was performed using the datasets published thus far. These findings might expedite the functional determination of the dehydration-responsive proteins and their prioritisation as potential molecular targets for better adaptation.Item Genotype independent regeneration and agrobacterium-mediated genetic transformation of sweet potato (Ipomoea batatas L.)(Bangladesh Association for Plant Tissue Culture and Biotechnology, 2013) Shekhar, Shubhendu; Agrawal, Lalit; Buragohain, Alak Kumar; Datta, Asis; Chakraborty, Subhra; Chakraborty, NiranjanDevelopment of an efficient genotype independent regeneration and genetic transformation system in sweet potato continues to be of great interest. Agrobacterium‐mediated genetic transformation protocol was established in two different cultivars of sweet potato using Agrobacterium strain EHA105 harbouring binary plasmid pBI121 containing GUS and nptII genes. The internodal stem segments from 30‐day‐old micropropogated plants were used as explant with different combinations of media and hormones. MS and LS media with various concentrations of growth regulators proved to be non‐responsive and the infecundity was severe with the addition of cytokinins. Nonetheless, MS with 2,4‐D and TDZ gave a good percentage of callusing but with low differentiation. In different concentrations of NAA, significant amount of callusing was observed but percentage of rooting remained low in both the genotypes. Gamborg’s B5 supplemented with NAA proved to be the most suitable media and hormone combination, which yielded shoot formation after 8 ‐ 10 weeks with a regenera‐ tion efficiency of 40 ‐ 70%. Stable integration of transgene was confirmed by PCR analysis. Furthermore, qRT‐PCR analysis was performed to assess the transcript accumulation in addition to the GUS enzymatic assay in the transgenic lines.